From Africa to Eurasia - Early dispersals

The dispersals of early hominins in the late Pliocene or early Pleistocene into Eurasia were essentially sporadic. Little geographic and temporal continuity is observed between the various dated archaeological contexts, and the lithic assemblages do not demonstrate a techno-morphological continuity. The archaeological evidence from 1.8 to 0.7 Ma indicates at least three waves of early migrations. The earliest sortie involved bearers of core-chopper industries sometime around 1.7-1.6 Ma. Early Acheulean producers followed possibly around 1.4 Ma. The third wave occurred sometime around 0.8 Ma, and is represented by Acheulean groups who manufactured numerous flake cleavers. The geographic scope of each of these waves is not yet well known. The reasons for 'why' early humans dispersed from Africa into Eurasia include the 'push' of environmental change and relative 'demographic pressure', as well as the opening of new niches. Humans may have gained their meat supplies either from carcasses or through active predation. The archaeological and fossil records demonstrate that Homo erectus was a successful species, and like other successful species it enlarged its geographic distribution at all costs. Even if the trigger for the initial dispersal of Homo erectus remains unknown or controversial, the success of the hominid occupation of the Eurasian habitats was not primarily facilitated by the availability of food, or the human flexibility in food procuring techniques, but by the absence of the zoonotic diseases that plagued and constrained hominins in their African 'cradle of evolution'. Once humans succeeded in crossing the disease-plagued belts of Africa the chances for survival of many more members of their groups rose steeply. It was only thereafter that humans could exploit their latent capacities and came to enjoy their global colonization.